The present invention relates to methods and apparatus for producing integrated circuit devices and to integrated circuit devices produced thereby and more particularly to an optronic integrally packaged die.
An essential step in the manufacture of all integrated circuit devices is known as xe2x80x9cpackagingxe2x80x9d and involves mechanical and environmental protection of a silicon chip which is at the heart of the integrated circuit as well as electrical interconnection between predetermined locations on the silicon chip and external electrical terminals.
At present three principal technologies are employed for packaging semiconductors: wire bonding, tape automatic bonding (TAB) and flip chip.
Wire bonding employs heat and ultrasonic energy to weld gold bonding wires between bond pads on the chip and contacts on the package.
Tape automatic bonding (TAB) employs a copper foil tape instead of bonding wire. The copper foil tape is configured for each specific die and package combination and includes a pattern of copper traces suited thereto. The individual leads may be connected individually or as a group to the various bond pads on the chip.
Flip chips are integrated circuit dies which have solder bumps formed on top of the bonding pads, thus allowing the die to be xe2x80x9cflippedxe2x80x9d circuit side down and directly soldered to a substrate. Wire bonds are not required and considerable savings in package spacing may be realized.
The above-described technologies each have certain limitations. Both wire bonding and TAB bonding are prone to bad bond formation and subject the die to relatively high temperatures and mechanical pressures. Both wire bond and TAB technologies are problematic from a package size viewpoint, producing integrated circuit devices having a die-to-package area ratio ranging from about 10% to 60%.
The flip-chip does not provide packaging but rather only interconnection. The interconnection encounters problems of uniformity in the solder bumps as well as in thermal expansion mismatching, which limits the use of available substrates to silicon or materials which have thermal expansion characteristics similar to those of silicon.
Optronic packages for semiconductors are known. Conventional optronic packages used for imaging employ a ceramic housing onto which is sealingly mounted a transparent window. Optronic packages used for low level imaging, light emission and radiation detection, including light detection, employ a clear plastic enclosure.
Described in applicant""s published PCT Application WO 95/19645 are methods and apparatus for producing integrated circuit devices, including, inter alia, integrally packaged dies having a radiation transparent protective layer.
The present invention seeks to provide optronic integrated circuit devices which are extremely compact as well as apparatus and techniques for the production thereof.
There is thus provided in accordance with a preferred embodiment of the present invention an integrally packaged optronic integrated circuit device including:
an integrated circuit die containing at least one of a radiation emitter and radiation receiver and having top and bottom surfaces formed of electrically insulative and mechanically protective material, at least one of the surfaces being transparent to radiation, and electrically insulative edge surfaces having pads.
Preferably, the device also includes at least one spectral filter associated with a radiation transparent protective surface thereof.
Additionally in accordance with a preferred embodiment of the present invention, the device includes a semiconductor substrate which is sufficiently thin as to enable to device to be responsive to back illumination.
Preferably, the device also includes at least one color filter associated with a radiation transparent protective surface thereof.
Further in accordance with a preferred embodiment of the present invention, lenses may be integrally formed on a transparent protective surface of the device.
Additionally in accordance with a preferred embodiment of the present invention, light coupling bumps may be integrally formed on a transparent protective surface of the device.
Further in accordance with a preferred embodiment of the present invention a waveguide and other optical components integrally formed on a transparent protective surface of the device.
Additionally in accordance with a preferred embodiment of the present invention, an optical grating may be integrally formed on a transparent protective surface of the device.
Further in accordance with a preferred embodiment of the present invention a polarizer may be formed on a transparent protective surface of the device.
There is also provided in accordance with a preferred embodiment of the present invention an integrally packaged optronic integrated circuit device including:
an integrated circuit die containing at least one of a radiation emitter and radiation receiver and having top and bottom surfaces formed of electrically insulative and mechanically protective material, at least one of the surfaces being transparent to radiation, the integrally packaged optronic integrated circuit device being characterized in that its longest dimension does not exceed the longest dimension of the die by more than 20%. Preferably the integrally packaged optronic integrated circuit device is characterized in that its longest dimension does not exceed the longest dimension of the die by more than 10%. More preferably the integrally packaged optronic integrated circuit device is characterized in that its longest dimension does not exceed the longest dimension of the die by more than 5%.
There is also provided in accordance with a preferred embodiment of the present invention a method for producing an integrally packaged optronic integrated circuit device comprising the steps of:
forming electrical circuits onto a semiconductor wafer;
forming at least one transparent mechanical protective layer onto said semiconductor wafer over said electrical circuits;
forming solderable contacts onto said semiconductor wafer; and
thereafter, dicing said wafer into individual packaged dies.